Thanks for all the replies, and especially the pics. I'm more convinced now that the best place is to tie into the back of the ROPS system in some way. I had a backpack type bag that a NWTF guy had given me, and decided it was just the right size for a hanging tool bag. I had in mind it being temporary when I attached it, but it works so well that I may just leave it on there. It has plenty of room in main compartment for all the tools I need, and also has a couple of side compartments. I keep the little metric wrench for tightening the nuts on the 3 pt hitch chains in one of them and its real handy. Here is what it looks like:
I think that's the best location for a rigid tool box if I decide to install one. I was thinking of putting one on this side before asking you guys:
I would have to remove the light and the grab handle to put it there, and a tool box is really more convenient in the rear anyway. I don't really need the light, but I do grab that handle often, especially when getting on the tractor. Glad to hear that others got some ideas from this thread.
This is a Fredrickson tractor I bought last summer and posted on here about the trouble I had. When they rebuilt it, the mechanic didn't get valve cover just right and it first leaked oil, then blew a head gasket. Fredrickson stood behind it and even picked it up and returned it without me ever having to haul it. It has been rock solid since. I even used it to pull a 2 bottom mold board plow to break my garden. I didn't need anyone to tell me that was way too much plow for the tractor, but I geared it down and went very slow and it handled it fine; temp never even got to the middle. I wouldn't use it for such tasks very long, but we are talking about an hour of work.
I have a 4' disk and an Andy 400 cutter and both pieces of equipment match up well with it. A 6' scrape blade keeps up my driveway, and I have a cultivator that I used for years with a 50 hp tractor. I had it set up for 2 rows with the big tractor, but just do one with the Yanmar. The rows are 40" instead of the 36" I've done in the past, but that's not an issue since I have plenty of room.
Another thing I added to the tractor that made life much easier was a Pat's Quick Hitch system. I tried to get by without it, but its so hard for me to line it up by myself. I have back problems, and trying to turn around and line it up just right every time I changed equipment was a big hassle. I had used a Pat's system on my JD5075 before, and didn't really like it because I have some type 2 equipment and some type 1. I finally bought a telescoping link system for it, but the Pat's works fine on the Yanmar since all the equipment is type 1. It made almost everything work better since it shifted the equipment 4" back. I was having trouble using my cutter and the disc without it, but the Pat's device solved those problems in addition to making it so much easier to change equipment by myself. Here is what it looks like if you have not seen one:
Thanks again for the help!